Electrical precipitator



April 0 J. H. HAMILTON 2,503,617

ELECTRICAL PRECIPITATOR Filed Feb. 1, 1946 3 Sheets-Sheet 1 FIG. I

mmvrozz. James Hugh Hamilton ATTORNEY April 11, 1950 Y J HAMILTON2,503,617

ELECTRICAL PRECIPITATOR Filed Feb. 1, 1946 5 Sheets-Sheet 2 I I9 ls I 1I6 I '20 III- a \F i I 9.9. 2| 22 {Ed- 1!" I I m i I l l I I l a I 25 lI I I 21 Q v 4 1% w a n pi a as F INVENTOR. Jams Hugh Hamilion ATTORNEYApril 11, 1950 Y J. H. HAMILTON 2,503,617

ELECTRICAL PRECIPITATOR Filed Feb. 1, 1946 s Sheets-Sheet? mmvrox. JamesHugh Hamilton ATTORNEY Patented Apr. 11, 1950 ELECTRICAL PRECIPITATORSalt Lake City, Utah, assignor to Western Precipitation Corporation, LosAngeles, Calif., a corporation of California Application February 1,1946, Serial No. 644,809

g 9 Claims. ,(Cl. 183-7) James Hugh Hamilton,

This invention relates to electrical precipitators and more particularlyto rapping devices'for removing accumulated material from electrodes ofelectrical precipitators by subjecting the electrodes to mechanicalshock.

An object of the invention is to provide an improved electrode rappingdevice utilizing a fluid pressure reaction jet for supplying therequired energy. Another object is to provide in such a device meanswhereby danger of short-circuiting or grounding of the electrodes may beeliminated.

A further object is to provide a relatively simple and sturdy electroderapper which may be automatically controlled and which requires aminimum of attention and maintenance.

Typically, the electrode rapping mechanism of the invention includes astriker member positioned in spaced relation to a member of an electrodestructure, a fluid pressure reaction jet orifice mounted in drivingrelation on one of the members, and means for intermittently supplyingfluid pressure to the reaction jet to urge the one member intoengagement with the other member.

The invention will be described hereinafter with greater particularity,reference being had to the accompanying drawings wherein:

Fig. 1 is a longitudinal sectional view of an electrical precipitatorembodying the invention, taken along the plane of the line l-l of Fig.2;

Fig. 2 is a transverse sectional view taken along the plane of the line2-2 of Fig. 1;

Fig. 3 is a fragmentary elevation of the lefthand end of the hightension electrode structure as seen in Fig. 1, parts being broken away.to

show interior construction;

Figs. 4 and 5 are detail views of the leftand right-hand ends,respectively, of the rapper bar looking in the direction of the arrows4-4 and 5-5 01 Fig. 1;

Fig. 6 is a plan view of form of the apparatus, and

Fig. '1 is an elevational view of the parts shown in Fig. 6.

parts of a modified potential electrical field is maintained by meanswell-known in the art. In the zones between such complementary electrodecurtains, ionization and precipitation of gas-borne particles occurs inwell-known manner.

Much of the precipitated matter adheres to the electrodes and must beperiodically removed if the apparatus is to function efliciently. Asspecifically disclosed herein, the electrode rapping mechanism isconstructed and arranged for rapping high tension electrodes, but aswill be readily apparent, it may be adapted, in the light of thedisclosure, to rap low tension electrodes or other similar structures.

Referrin to Figs. 1 and 2, it will be seen that the high tensionelectrode structure and rapping mechanism are completely insulated fromthe housing l0, being mounted on insulators l6 and [1. As' will morefully appear hereinafter, a rubber or other insulating hose [8 preventsgrounding of the high tension electrode structure. Insulators I6 carry,in suitable bearings, a lateral pipe I9, from the ends of which dependnipples 20. A second length of lateral pipe 2|, provided with cappedends, is connected to the nipples 20 by Ts. Pipe 2! has the dualfunction of supporting the left ends of the high tension electrodesupporting bars '22 and providing a header for distributing fluid underpressure to the flexible lines 23. The fluid preferably is compressedair or other gas and is obtained from a'source, such as the tank 24, andled to the header 2| through suitable conduits including hose l8, pipe19 and nipples 29.

Lines 23 maybe made from lengths of pipe formed with a coiled turn 25 toprovide flexibility or resiliency at the lower ends of the lines in thedirection of gas flow, together with relative lateral rigidity. Thelower ends of the lines are fitted with nozzles or reaction jets 26.Rapper bars 2'! are supported at their left ends by the lines 23.

The high tension electrode supporting structure located near the outletend of the precipitator issimilar to that just described, but it doesnot provide a pressure fluid system nor any reaction jets; its solefunction is to carry the right end of the high tension electrodestructure.

As best seen in Fig. 5, a slot 28 is formed near the right end of rapperbar 2? through which extends a rigid vertical guide 29, the rapper barbeing mounted in a sling 30 for limited longitudinal movement withreference to the guide.

The discharge electrode elements l4 may take the form of twisted squaremetal rods provided electrode elements.

with hooks at their tops, as best seen in Fig. 3. These elements areinserted in suitable holes in the electrode supporting bars 22 anddepend through longitudinal slots 3| provided in the rapper bars 21.

In operation, a rapper bar 2'! is intermittently driven longitudinallyagainst the elctrode elements received in its slots 3| by intermittentreaction of its jet 2B. Slots 3| are elongated longitudinally of rapperbars 21, that is, they are elongated in the direction of movement of thebar. In the normal or rest position illustrated in Figs. 3, 4 and 5, theleft end face of each slot 3! is spaced from the electrode element i4received in the slot. Under the force of the reaction to fluid issuingfrom jet 26, bar 21 first moves freely a limited distance transverselyof the electrode elements and thus gains momentum before the normallyspaced end face of each slot 3i strikes the electrode member therein.The bar 2'! thus acts as a striker bar which because of the clan-- gatedcharacter of apertures 31 is driven sharply against the electrodeelements by its movement transversely thereof. Such action jars theelectrode elements and effectively dislodges deposited dust or othermatter which falls into the hopper I 3. The intermittent action iscontrolled by a solenoid valve 32 positioned in the line from the sourceof pressure fluid, the valve being actuated at preselected intervals topass to the jets increments of fluid under pressure. Action of the valvemay be timed by an automatic timing switch (not shown) Preferably, thevalve 32 provides a series of impulses at intervals of a few seconds.impulse, the valve is open for only a fraction of a second, so that thereaction force of the jet is stopped before the rapper bar reaches theend of its stroke, the momentum of the bar being sufficient to bring itinto shock contact with the A further rapping contact with the electrodeelements occurs when the rapper bar returns toward its. rest position.The interval between successive impulses should be sufficient to allowthe swinging movement of the rapper bar to subside, an interval of aboutthree to five seconds usually being suflicient for this purpose,

The rest position of the rapper bar may be determined by gravity, by theposition of the right end of the slot 28 in which the guide is received,by a combination of the two, or by other appropriate means. The coiledsupporting line 23 provides a resilient mounting for the rapper bar-that':biases the bar toward a normal rest position as determined byengagement of the right end of the slot 28 with the rapper bar, in whichthe left-hand end faces of slots 3| are spaced from electrodes l4.

It will be understood that a suitable source of high potential isconnected to the complementary electrode curtains l4 and i in the usualway. As shown, the collecting electrodes 65 are grounded to the housingand the high tension electrode structure is insulated therefrom.

In the specific apparatus illustrated, the collecting electrodes may becleaned in any desired way, as by manual rapping, flushing with liquidor the like.

The modified embodiment of the invention shown in Figs. 6 and '7 differsfrom that hereinbeiore described in that the electrode elements M do notride in slots in the loweror tie-bar 21 but are secured firmly to thelatter, whereby the free ends of the electrode elements may be flexed inunison. The lower bar 21' is, in efiect, an in- On each tegral part ofthe high tension electrode curtain. It is intermittently driven by thereaction jet 26 into jarring engagement with a fixed insulated anvil orstriker 33, the shock of its impact against the striker member 33 beingtransmitted to the electrode elements 14 to dislodge adhering matter. Astop 34, also insulated from the housing, acts as a striker on thereturn movement of the lower bar 21'.

From the foregoing description, it will be seen that there has beenprovided an electrode rapping mechanism utilizing fluid pressure jetreaction to obtain simple and efiective rapping of material collectingmembers, and that various modifications may be made in the form andarrangement of the elements without departing from the principles of theinvention as defined in the claims.

I claim:

1. In an electrical precipitator including complementary electrodes oneof which comprises a curtain of spaced electrode elements, an electroderapping mechanism which comprises a rapping bar providing a plurality ofspaced elongated apertures loosely receiving said elecspaced elongatedapertures loosely receiving the lower ends of said electrode elements,means mounting said rapping bar for limited oscillatory movement, fluidpressure reaction jet means mounted in driving relation on said rappingbar, and means for intermittently supplying fluid pressure to saidreaction jet means todrive said rapping bar sharply against saidelectrode elements.

3. In an electrical precipitator, a high tension electrode structure andrapping mechanism which comprises an upper longitudinal electrodesupporting bar, insulating means mounting said supporting bar in theprecipitator, a plurality of spaced electrode elements suspended fromsaid bar, a longitudinal electrode rapping bar providing a plurality ofspaced elongated apertures loosely receiving the lower ends of saidelectrode elements, said rapping bar being substantially parallel tosaid supporting bar, means suspending said rapping bar from saidinsulating means for limited oscillatory movement substantially parallelto said supporting bar, fluid pressure reaction jet means mounted indriving relation on said rapping bar, and means'for' intermittentlysupplying fluid pressure to said reaction jet means to drive saidrapping bar sharply against said electrode elements.

4. In an electrical precipitator, a high tension electrode structure andrapping mechanism which comprises insulating means supporting aplurality of spaced, parallel high tension electrode elements in theprecipitator, one end of each element being fixed in said supportingmeans, the other end of each element being free to flex, a tie-barjoining said other ends of said electrode elements whereby said otherends may be flexed in unison, a relatively fixed striker memberpositioned in normally spaced relation to said tie-bar, fluid pressurereaction jet means mounted in driving relation on said tie-bar, andmeans for intermittently supplying fluid pressure to said reaction jetmeans to drive said tie-bar sharply against said striker member.

5. In an electrical precipitator having an electrode structure whichcomprises a curtain of spaced parallel electrode elements, an electroderapping mechanism which comprises: a rapping bar mounted for limitedmovement transversely of the electrode elements and provided with aplurality of apertures elongated in the direction of said movement forreceiving the electrode elements; a fluid reaction jet mounted on therapping bar; and means for supplying fluid under pressure to said jet,whereby the rapping bar is moved by the reaction to the fluid issuingfrom the jet to strike all the electrode elements.

6. In an electrical precipitator having an electrode structure whichcomprises a curtain with spaced parallel electrode elements, anelectrode rapping mechanism which comprises: a rapping bar provided witha plurality of apertures elongated longitudinally of the bar; resilientsuspension means for the rapping bar supporting the bar for limitedlongitudinal movement and biasing the bar toward a normal position inwhich the faces at one end of the apertures are normally spaced from theelectrode elements; a fluid reaction jet mounted on the rapping bar; andmeans for supplying fluid under pressure to said jet, whereby therapping bar is moved by the reaction to the fluid issuing from the jetto strike all the electrode elements.

7. An electrode rapping mechanism comprising a striker member having aface normally positioned in spaced relation to a member of an electrodestructure, one of said members being movable into contact with the otherofsaid members, jet forming nozzle means mounted on said one member in aposition to move said one member 40 by force derivedfrom the reaction tothe jet,

and means for intermittently supplying fluid under pressure to said jetforming nozzle means to drive said one member sharply against the otherof said members.

8. An electrode rapping mechanism comprising a striker member having aface normally positioned in spaced relation to a member of an electrodestructure, said striker member being movable into contact with theelectrode member, jet forming nozzle means mounted on the striker memberin a position to move said member by force derived from the reaction tothe jet, and means for intermittently supplying fluid under pressure tosaid jet forming nozzle means to drive said striker member sharplyagainst the electrode member.

9. An electrode rapping mechanism comprising a striker member having aface normally positioned in spaced relation to a member of an electrodestructure, said electrode member being movable into contact with thestriker member, jet forming nozzle means mounted on the electrode memberin a position to move said member by force derived from the reaction tothe jet,

and means for intermittently supplying fluid under pressure to said jetforming nozzle means to drive said electrode member sharply against thestriker member.

JAMES HUGH HAMILTON.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,981,455 Knight Nov. 20, 1939FOREIGN PATENTS Number Country Date 469,697 Germany Mar. 24, 1926

